Calibration of gyratory compactor apparatuses and associated methods

ABSTRACT

A method for calibrating a gyratory compactor apparatus is provided. The gyratory compactor apparatus is of the type being configured to compact and impart an orbital motion to a sample in a mold that defines a mold axis and includes at least one actuator for imparting lateral displacement of the mold relative to a longitudinal axis of the gyratory compactor apparatus. The method includes the steps of imparting lateral orbital displacement of the mold relative to the gyratory compactor apparatus by actuation of the at least one actuator to thereby define a gyratory angle between the gyratory compactor apparatus and the mold axis, measuring the gyratory angle, and determining adjustments to actuation of the at least one actuator based on the measured gyratory angle and a target angle. An associated apparatus and method for calibrating the apparatus are also included.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Patent ApplicationNo. 61/143,529, filed on Jan. 9, 2009, the content of which isincorporated herein in its entirety. The disclosures of the followingUnited States Utility patent applications, commonly owned andsimultaneously filed herewith, are all incorporated by reference intheir entirety: GYRATORY COMPACTOR APPARATUSES AND ASSOCIATED METHODS(Ser. No. 12/685,482); and GYRATORY COMPACTOR APPARATUSES AND ASSOCIATEDMETHODS (Ser. No. 12/685,498).

TECHNICAL FIELD

The presently disclosed subject matter relates to gyratory compactorapparatuses and associated methods. More particularly, the presentlydisclosed subject matter relates to improved gyratory compactorapparatuses and associated devices and methods.

BACKGROUND

In order to measure certain physical properties, such as density,moisture content and compressive strength of some materials such as soilor paving material, loose samples of the soil or paving material areformed into test specimens under reproducible conditions usinglaboratory compaction machines. In order to replicate actual expectedconditions, it is desirable to compact the test specimens underconditions that simulate actual use. For a paving material sample, thisrequires simulation of the kneading force applied to the paving materialby a paving roller, such as rollers with smooth or sheeps/pad-foot drumsor pneumatic wheels, or vibratory compactors such as those used inintelligent compaction. Simply applying a compressive force to thesample does not adequately simulate the kneading action of the pavingroller, as the paving roller also applies a shear force to the materialbeing compacted. As a result, compaction machines that apply an orbitalmotion to the paving sample during compression have been developed tosimulate actual conditions of use. For simplicity of implementation andanalysis, the orbital motion in many current compaction machines hasbeen restricted to gyration along a circular orbit.

The combination of shear and compaction effort applied to the gyratingspecimen is designed to mimic the kneading effect of in-situ compactionof a material using a rolling compactor. Typically, the gyration of themold is performed with an offset so that the axis of the mold is at anangle from the compression force from the ram. The corresponding averageangle between the direction of the compression force and the position ofthe mold axis is often referred to as the internal angle.

This internal angle is the angle of applied confinement forces withrespect to the main axis of rotation that the specimen is really subjectto. Its measurement and calibration is typically performed using aself-contained device such as the Rapid Internal Angle Measurement (RAM)unit, an example of which is disclosed in U.S. Pat. No. 6,925,889, orDynamic Angle Validator (DAV), an example of which is disclosed in U.S.Pat. No. 6,477,783B1. These devices are shear force simulation devicesthat mimic the shear effort applied to a material and have thecapability to also measure, store, and display the internal angle by wayof difference of distance measurement of the position of the inside ofthe mold with respect to the perpendicular direction to a mold plate. Asimple way to infer the internal angle applied to the sample material isto measure the external angle, i.e., the angle between the referenceframe and the mold. However, when forces are applied to the frame andthe mold, the frame can flex, the ram position and direction of forcecan vary, and the corresponding perpendicular direction of the moldplates can change with respect to the inside axis of the mold. These arenot the exhaustive list of factors that can affect the actual internalangle versus the measured internal angle. They are, however, the mainvariables that can make the relationship between internal angle andexternal angle vary in time between the top and bottom of the sample.

Various disadvantages have been associated with previously developedgyratory compactors. For example, some gyratory compactors include a ramapplying compressive force from one end of a cylindrical mold, while theother end of the mold is gyrated by rotating a base supporting the otherend of the mold. However, these machines could not easily determine andmaintain a consistent angle of gyration due to inconsistencies duringrotation of the base supporting the other end of the mold and flexure ofthe gyratory compactor during operation. Most implementations includedthe use of a mechanical interference to constrain the shape of thegyration motion.

Another example of a gyratory compactor apparatus is disclosed in U.S.Pat. No. 5,939,642 to King et al. (the '642 patent). The '642 patentdescribes a gyratory compactor apparatus design for facilitatingergonomics and efficiency, while improving consistency of operatingparameters. The gyratory compactor described therein allows the user toslide the cylindrical compaction mold into the compaction chamberwithout the necessity of lifting the mold. In addition, the compactor ofthe '642 patent includes an integral specimen removal ram, whichfacilitates easy removal of the specimen from the mold. In addition, theframe design reduces frame deflection that could undesirably affect theangle of gyration. Further, the angle of gyration of the compactorapparatus can be changed by simply replacing a single component of theapparatus. Notwithstanding the advances that have been made in the artof gyratory compactors, there is a need for smaller and less costlydesigns, with improved operational efficiency and accuracy.Additionally, there is a need for a gyratory compactor having improvedergonomics. For example, placement and removal of the mold containingthe sample should be accomplished with minimal difficulty. Additionally,it would be desirable to produce a lightweight frame design that alsominimizes frame flexure, thus providing more accurate test results.Moreover, it would be advantageous to enable release of water contentwhen the sample material is fully or partially saturated soil oremulsified asphalt. Also, it would be advantageous to provide acompactor design that allows the user to quickly, easily, dynamically,and/or in real-time change, control, and calibrate operating parameters,such as the angle of gyration, shape of gyration, and ability to controlapplied axial load. Further, there is a need in the art for a gyratorycompactor that provides a constant, precise, and accurate internal angleof gyration during the compaction procedure with minimal deviationtherefrom.

SUMMARY

According to one aspect, a gyratory compactor apparatus is provided. Thecompactor apparatus is adapted to interact with a mold that defines amold axis. The gyratory compactor apparatus includes a frame defining aframe axis and having a first mounting plate and a spaced-apart secondmounting plate and a pivoted support carried by the frame and capable ofrotation in at least a first and a second rotational degree of freedom.A mold-engaging device is carried by the pivoted support and has a firstcarriage plate proximal the pivoted support and a second carriage plateaxially spaced-apart from the pivoted support for receiving the moldtherebetween. The second carriage plate is laterally moveable relativeto the frame axis by rotation of the pivoted support in either of thefirst or second degrees of freedom. At least one actuator having a firstend carried by the frame and a second end carried by the second carriageplate for imparting lateral translation to the second carriage platerelative to the frame axis is provided. A gyratory internal angle isdefined between the frame axis and the mold axis.

According to another aspect, the second carriage plate is axiallytranslatable about the mold axis.

According to another aspect, the mold-engaging device is slideablycarried by the pivoted support.

According to another aspect, the mold-engaging device further includesan actuator for providing clamping forces to the mold-engaging deviceand imparting axial translation of the second carriage plate.

According to another aspect, the pivoted support is a gimbal.

According to another aspect, the compactor apparatus also includes a ramrod in generally axial alignment with the frame axis for providingrotational movement and compressive forces to the mold about the frameaxis.

According to another aspect, the compactor apparatus also includes aposition sensor in communication with the ram rod.

According to another aspect, the compactor apparatus also includes ananti-rotate plate on a distal end of the ram rod and further including aplurality of spaced-apart support beams carried on a first end about aperiphery of the anti-rotate plate and carried on a second end at thesecond mounting plate for providing torsional rigidity to retardtorsional strain imparted from rotation of the ram rod.

According to another aspect, each actuator of the at least one actuatoris a hydraulic actuator.

According to another aspect, each actuator of the at least one actuatoris independently controlled relative to each other actuator.

According to another aspect, the compactor apparatus also includes adisplacement measurement device in communication with each actuator ofthe at least one actuator for measuring displacement of each actuator.

According to another aspect, each of the at least one actuators define alongitudinal axis between the first end and the second end of eachactuator, and an actuation angle is formed relative to the longitudinalaxis of each actuator and the frame axis, and wherein the actuationangle is about 23 degrees.

According to another aspect, each actuator of the at least one actuatoris carried by the first mounting plate.

According to another aspect, the mold is a mold of the type having anelongate cylinder that defines a cavity therein for receiving thesample.

According to another aspect, the mold is of the type having aperipherally extending flange extending from the cylinder at a first endand a second end thereof.

According to another aspect, an alternate embodiment of gyratorycompactor apparatus adapted to interact with a mold that defines a moldaxis is provided. The gyratory compactor apparatus includes a framehaving a first mounting plate and defining a frame axis extending fromthe first mounting plate, a pivoted support carried by the frame, afirst carriage plate moveable in response to movement of the pivotedsupport, and a second carriage plate spaced-apart from the firstcarriage plate, the second carriage plate being attached to the firstcarriage plate by at least one clamping rod extending therebetween. Aram rod is in general alignment with the second carriage plate forproviding compressive and gyratory forces to a mold held between thefirst and second carriage plates. At least one actuator carried on afirst end by the frame and on a second end by the second carriage plateis provided. The actuator is operable to offset the second carriageplate relative to the frame axis such that during gyration of the mold.This offset defines a gyratory internal angle between the frame axis andthe mold axis.

According to another aspect, the gyratory compactor apparatus includes amold-engaging device that is slideably carried by the pivoted support.

According to another aspect, the at least one actuator that impartsaxial translation applies a predetermined axial load or force andcorrects the internal angle accordingly.

According to another aspect, the mold engaging device also includes atranslation mechanism for imparting axial translation of and providingclamping forces to the second carriage plate.

According to another aspect, a method for testing a sample containedwithin a mold for a gyratory compactor apparatus is provided. Thegyratory compactor apparatus has a frame that carries a mold-engagingdevice having a pivoted support, a first carriage plate moveable inresponse to movement of the pivoted support, a second carriage platespaced-apart from the first carriage plate for receiving the moldtherebetween, and at least one actuator carried on a first end by theframe and on a second end at the second carriage plate. The methodincludes the steps of placing a mold in engagement with themold-engaging device, rotating the mold, and then imparting lateraldisplacement of the mold relative to the frame axis by actuation of theat least one actuator to thereby define a gyratory internal anglebetween the frame axis and the mold axis.

According to another aspect, the gyratory compactor apparatus furtherincludes a ram rod in general alignment with the mold for compacting themold, and the method also includes the step of compacting the mold withthe ram rod.

According to another aspect, the gyratory compactor apparatus includesthe step of measuring the compaction of the compacted material in themold.

According to another aspect, the mold is rotated about the ram rod.

According to another aspect, the method also includes the step ofmeasuring the gyratory angle. The internal angle can be directlymeasured using sensors or devices such as a DAV, RAM, or at least oneinclinometers in operational relation with at least one of internal orexternal lateral surfaces of the mold.

According to another aspect, the method also includes the step ofcalibrating the angle. The calibration step includes the step ofinferring the position or length of at least one of the actuators intoan external angle. This external angle and the compressive force appliedto the sample material to be included to calibrate the internal anglethat is actually perceived by the sample under test. The calibrationprocess can use a moment simulation device and/or internal anglemeasurement device such a RAM unit or a DAV.

According to another aspect, the method also includes the step ofmeasuring the at least one internal or external radial forces. Themeasurement of the at least one direction of the forces can be donedirectly by way of at least one force, pressure or load sensor that canbe selected from mechanical, optical, electrical, piezoelectric,electromechanical sensors such load cells, pressure transducers,calibrated displacement measurement transducers, energy dissipation andthe like. The transducers monitor at least one of the transducers and/orthe ram head, and/or the clamping devices.

According to another aspect, the method also includes the step ofcontrolling the at least one internal or external radial forces appliedto the sample material. This step can take into account the anisotropicbehavior of the overall gyratory assembly flexure under differentcompressive pressures applied to the sample, wherein varying compressiveforces and structural rigidity causes anisotropic behavior of flexure ofthe gyratory compactor apparatus. Examples of cause and location offlexures include and are not limited to actuator, gimbal, frame, plateassemblies, ram head and/or shaft flexures.

According to another aspect, the method also includes the step ofapplying a predetermined moment on the sample material. The moment maybe constant in time, varying in time, with or without a periodiccomponent. Once the predetermined moment is applied, the method mayinclude the control of the angle inducing the correspondingeccentricity.

According to another aspect, the method also includes the step ofapplying a predetermined moment on the sample material. The moment maybe continuous in time, varying in time, with or without a periodiccomponent.

According to another aspect, the measurement of the gyratory internalangle is measured instantaneously for each rotation of the mold relativeto each rotation of the mold. The measurement of the gyratory angle mayalso be averaged for each rotation of the mold. The measurement can beperformed directly without limitation by at least one inclinometeroperative to the inside or outside of the mold or an angle measurementdevice such as the RAM/DAV, or the measurement can be performedindirectly by the location of at least one of the carriage plateassemblies or the position of at least one actuator lengths. Thesemeasurements can be taken continuously or at least one predeterminedposition in the orbit of the motion, or at least one predetermined timeof operation including at predetermined intervals of times.

According to another aspect, in the step of imparting lateraldisplacement of the mold relative to the frame axis by actuation of theat least one actuator, the at least one actuator is a hydraulic actuatorin communication with a hydraulic source.

According to another aspect, the vertical force applied to the samplematerial is modeled to a predetermined waveform. The user can select thecharacteristic of the waveform including and not limited to the shapesuch as sinusoidal, triangular and the parameters associated with suchwaveform, including but not limited to the amplitude, phase, offset,dynamic range, time delay, and other various parameters.

According to another aspect, a gyratory compactor apparatus is providedthat is adapted to interact with a mold defining a mold axis. Thegyratory compactor apparatus includes a ram rod in generally axialalignment with the mold axis for providing compressive forces to themold about the mold axis. The compressive forces provided by the ram rodto the mold models a predetermined waveform.

According to another aspect, the waveform is a sinusoidal waveform.

According to another aspect, the waveform is a triangular waveform.

According to another aspect, the waveform is a saw-tooth waveform.

According to another aspect, the waveform is a square waveform.

According to another aspect, the apparatus also includes a signalgenerator in communication with the ram rod for providing thepredetermined waveform.

According to another aspect, a method for compacting a sample containedwithin a mold for a gyratory compactor apparatus is provided. Thegyratory compactor apparatus is of the type having a mold-engagingdevice and includes the steps of placing the mold in engagement with themold-engaging device and imparting compressive forces to the mold inorder to compact the sample contained therein. The compressive forcesare imparted according to a predetermined waveform.

According to another aspect, a gyratory compactor apparatus is providedthat is adapted to interact with a mold that defines a first end and aspaced-apart second end. The gyratory compactor apparatus includes amold-engaging device having a carriage plate assembly for engaging arespective one of the first or second ends of the mold. The carriageplate assembly has a first engagement surface for engaging therespective one of the first or second ends of the mold. At least one ofthe first engagement surface, the first end of the mold, or thespaced-apart second end of the mold includes at least one texturalfeature for providing anti-slip characteristics between the firstengagement surface and the respective one of the first or second ends ofthe mold.

According to another aspect, the textural feature comprises at least onegroove.

According to another aspect, the textural feature comprises etching.

According to another aspect, the textural feature comprises chiseling.

According to another aspect, the textural feature comprisessandblasting.

According to another aspect, the textural feature comprises a frictionincreasing coating.

According to another aspect, the first engagement surface defines atextural feature.

According to another aspect, the first end of the mold defines atextural feature.

According to another aspect, the spaced-apart, second end of the molddefines a textural feature.

According to another aspect, the carriage plate assembly includes asecond engagement surface spaced-apart from the first engagement surfacewhich defines a space therebetween for receiving the mold. The secondengagement surface engages the other of the respective one of the firstor second ends of the mold.

According to another aspect, the second engagement surface defines atextural feature.

According to another aspect, the first engagement surface includes atextural feature and the first end of the mold includes a texturalfeature. The textural feature of the first engagement surface and thetextural feature of the respective one of the first or second ends ofthe mold are configured to matingly engage and thereby increase axialfriction at the engagement of the first engagement surface and therespective one of the first or second ends of the mold.

According to another aspect, the mold is a mold of the type having anelongate cylinder that defines a cavity therein for receiving thesample, and having a peripherally extending flange extending from thecylinder at a first end and a second end thereof.

According to another aspect, the mold is a mold of the type having anelongate cylinder that defines a cavity therein for receiving thesample, and the mold does not have a peripherally extending flangeextending from the cylinder at a first end and a second end thereof.

According to another aspect, the mold is a mold of the type consistingof an elongate cylinder that defines a cavity therein for receiving thesample.

According to another aspect, a method for calibrating a gyratorycompactor apparatus is provided. The gyratory compactor apparatus is ofthe type being configured to compact and impart an orbital motion to asample in a mold that defines a mold axis and includes at least oneactuator for imparting lateral displacement of the mold relative to alongitudinal axis of the gyratory compactor apparatus. The methodincludes the steps of imparting lateral orbital displacement of the moldrelative to the gyratory compactor apparatus by actuation of the atleast one actuator to thereby define a gyratory angle between thegyratory compactor apparatus and the mold axis, measuring the gyratoryangle, and determining adjustments to actuation of the at least oneactuator based on the measured gyratory angle and a target angle.

According to another aspect, the method also includes the step ofmeasuring a force exerted on the mold, and wherein determiningadjustments to actuation comprises determining adjustments to actuationof the at least one actuator based on the measured force.

According to another aspect, in the step of measuring the gyratoryangle, the step includes measuring the gyratory angle relative to eachrotation of the mold.

According to another aspect, in the step of imparting lateral orbitaldisplacement, the step includes imparting lateral orbital displacementof the mold relative to the gyratory compactor apparatus by actuation ofa hydraulic actuator in communication with a hydraulic source.

According to another aspect, a gyratory compactor apparatus is provided.The gyratory compactor apparatus is of the type being adapted tointeract with a mold that defines a mold axis and includes at least oneactuator configured to impart lateral orbital displacement of the moldrelative to the gyratory compactor apparatus to thereby define agyratory angle between the gyratory compactor apparatus and the moldaxis. A control system is provided and is configured to determineadjustments to actuation of the at least one actuator based on ameasurement of the gyratory angle and a target angle control actuationof the at least one actuator based on the determined adjustments.

According to another aspect, the gyratory compactor apparatus includes aforce sensor configured to measure a force exerted on the mold. Thecontrol system is configured to determine adjustments to actuation ofthe at least one actuator based on the measured force.

According to another aspect, each actuator of the at least on actuatoris independently controlled by the control system.

According to another aspect, each actuator of the at least one actuatoris a hydraulic actuator.

According to another aspect, a method for calibrating a gyratorycompactor apparatus configured to compact and impart a displacement to asample in a mold that defines a mold axis is provided. The gyratorycompactor apparatus includes at least one actuator for imparting lateraldisplacement of the mold relative to a longitudinal axis of the gyratorycompactor apparatus. The method includes the steps of inserting a momentsimulation device in a mold to apply a predetermined moment, impartinglateral displacement of the mold relative to the gyratory compactorapparatus by actuation of the at least one actuator to thereby define agyratory angle between the gyratory compactor apparatus and the moldaxis, measuring the actual moment, applying a compression force onto themold to thereby generate an actual moment, measuring at least one forceapplied by the at least one actuator, and determining a relationshipbetween the measured at least one force applied by the at least actuatorand the applied moment.

According to another aspect, the method includes the step of determininga corrective parameter for the moment simulation device based on thedetermined relationship.

According to another aspect, the method includes the step of storing thecorrective parameter.

According to another aspect, the method includes the step of filteringthe measurement of the at least one force.

According to another aspect, the method includes the step of displayingthe measurement of the actual moment.

According to another aspect, the method includes the step ofinterpolating and extrapolating at least one correction for differentpredetermined forces exerted on the mold.

According to another aspect, a gyratory compactor apparatus adapted tocompact and impart an orbital motion to a sample in a mold that definesa mold axis is provided. The gyratory compactor apparatus includes atleast one actuator configured to impart lateral orbital displacement ofthe mold relative to the gyratory compactor apparatus to thereby definea gyratory angle between the gyratory compactor apparatus and the moldaxis, a device configured to apply a compression force onto the mold,and at least one sensor configured to measure at least one force appliedby the at least one actuator. A control system is provided that isconfigured to control the gyratory compactor apparatus to vary theorbital motion to match a predetermined moment to be exerted on thesample.

According to another aspect, the control system is configured todetermine a corrective parameter for the moment simulation device.

According to another aspect, the control system is configured to storethe corrective parameter.

According to another aspect, the control system is configured to filterthe measurement of the at least one force.

According to another aspect, the gyratory compactor apparatus furtherincludes a display configured to display the measurement of the actualmoment.

According to another aspect, the gyratory compactor apparatus furtherincludes a display configured to display one of error of the measurementof the actual moment from a target moment, a three-dimensionalrepresentation of the actual moment, shear pressure, shear moment,eccentricity, eccentricity vector, or any other information related tomoments, passing or failing criteria of target moment information.

According to another aspect, the gyratory compactor apparatus furtherincludes a display configured to display one of the measurement of theactual angle or corresponding error from the prescribed value, thethree-dimensional representation of the angle, and average angle pergyration.

According to another aspect, the gyratory compactor apparatus furtherincludes a memory configured to store one of the measurement of theactual angle or corresponding error from the prescribed value, thethree-dimensional representation of the angle, and average angle pergyration.

According to another aspect, the control system is configured tointerpolate and extrapolate at least one correction for differentpredetermined forces exerted on the mold.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofvarious embodiments, is better understood when read in conjunction withthe appended drawings. For the purposes of illustration, there is shownin the drawings exemplary embodiments; however, the presently disclosedsubject matter is not limited to the specific methods andinstrumentalities disclosed. In the drawings:

FIG. 1 is a perspective view of a gyratory compactor apparatus accordingto an embodiment of the presently disclosed subject matter;

FIG. 2 is an enlarged, front view of a gyratory compactor apparatusaccording to an embodiment of the presently disclosed subject matter;

FIG. 3 is an enlarged, side view of a gyratory compactor apparatusaccording to an embodiment of the presently disclosed subject matter;

FIG. 4 is an upward facing perspective view of a mold engaging devicefor use with the gyratory compactor apparatus;

FIG. 5 is an upward facing perspective view of the mold engaging deviceshown in FIG. 4 having a mold engaged therewith for receiving aconstruction sample;

FIG. 6 is a cross-sectional view of a mold engaging device of thegyratory compactor apparatus according to an embodiment of the presentlydisclosed subject matter;

FIG. 7A is a side view of the mold showing the gyratory internal angledefined between the frame axis and the mold axis during gyration of themold according to an embodiment of the presently disclosed subjectmatter;

FIG. 7B a side view of the mold shown in FIG. 7A where the mold has beenrotated half of a rotation about the frame axis;

FIG. 8 is a front view of a ram rod and anti-rotation plate for use withthe gyrator compactor apparatus according to an embodiment of thepresently disclosed subject matter;

FIG. 9 is a downward facing, perspective view of the ram rod andanti-rotation plate shown in FIG. 8 for use with the gyratory compactorapparatus according to an embodiment of the presently disclosed subjectmatter;

FIG. 10 is a perspective view of a mold of the type for being used withthe gyrator compactor apparatus according to an embodiment of thepresently disclosed subject matter;

FIG. 11 is a perspective view of the mold shown in FIG. 9 having asample of material shown in an exploded view for being depositedtherein;

FIG. 12 is an enlarged, side view of the gyratory compactor apparatus incommunication with a control system for outputting predeterminedwavefunctions for controlling vertical translation of the ram rod;

FIG. 13 is an upward facing perspective view of a mold engaging devicehaving an engagement surface with a textural feature defined thereon;

FIG. 14 is a perspective view of a mold of the type for being used withthe gyratory compactor apparatus and having a textural feature definedon at least one end of the mold;

FIG. 15 is a flow chart of an exemplary process for calibrating agyratory compactor apparatus in accordance with an embodiment of thepresently disclosed subject matter; and

FIG. 16 is a flow chart of another exemplary process for calibrating agyratory compactor apparatus in accordance with this embodiment of thepresently disclosed subject matter.

DETAILED DESCRIPTION

The presently disclosed subject matter now will be described more fullyhereinafter with reference to the accompanying drawings, in which some,but not all embodiments are shown. Indeed, this invention may beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein; rather, these embodiments areprovided so that this disclosure will satisfy applicable legalrequirements. Like numbers refer to like elements throughout.

A gyratory compactor apparatus is shown throughout the Figures and isgenerally designated 10. The gyratory compactor apparatus 10 broadlyincludes a cart 1 with a plurality of wheels 2 attached thereto forproviding rolling movement of the cart 1 over a floor. A plurality ofupright supports 3 add increased structural integrity to the cart 1 anddefine openings therebetween for providing access to various componentsof the gyratory compactor apparatus 10. A hinged door 4 may also beprovided for selective access into the internal components of thegyratory compactor apparatus 10. A display panel 80 is provided fordisplaying various desired parameters. Security switches may also beprovided to transmit information to a control system 90 to disablemotion, reset the gyratory compactor apparatus 10 to a safe position, orto shut-off power to the gyratory compactor apparatus 10. The switchesmay be electromechanical, electrical, or any other suitable type switch.

As generally shown in FIGS. 2 through 6, the gyratory compactorapparatus 10 generally includes a frame 12 that defines a frame axis 14and includes a first mounting plate 16 and a spaced-apart secondmounting plate 20. The frame 12 is preferably constructed usingappropriate grade metal for increased structural rigidity, but is notlimited to any particular material, or any particular method ofconstruction. A pivoted support 22 is provided that is capable ofrotation in at least a first and a second rotational degree of freedom,and that is carried by the first mounting plate 16.

A mold-engaging device, generally designated as 30, is provided forreceiving and engaging a mold 70 that contains a material to be testedduring compaction. The mold-engaging device 30 has a first carriageplate 32 positioned proximal the pivoted support 22 and a secondcarriage plate 34 spaced-apart therefrom to form a carriage plateassembly. Collectively, the first carriage plate 32 and the secondcarriage plate 34 define a space therebetween to receive the mold 70.The first carriage plate 32 is moveable in response to movement of thepivoted support 22, and likewise, movement of the pivoted support 22imparts movement of the second carriage plate 34. The carriage plates 32and 34 are shown throughout the figures in a flat, saucer pan-likeconfiguration, but are not so limited by the claims and may take anyappropriate shape.

As shown in FIG. 2, at least one actuator 36 is provided for generatinga gyratory offset of the mold 70 during compaction. The actuator 36includes a first end carried by the frame 12 and a second end carried bythe second carriage plate 34 that allows motion along at least twodegrees of freedom. The actuator 36 imparts lateral movement to thesecond carriage plate 34 relative to the frame axis 14 to thereby definea gyratory internal angle α between the frame axis 14 and the mold axis72, as shown in further detail in regards to the descriptionaccompanying FIG. 7. A second actuator, also designated 36, is provided.In some embodiments, it may be preferable to use only one actuator 36,or in other embodiments, it may be desirable to include multipleactuators 36. For purposes of description only, the gyratory compactorapparatus 10 is shown with two actuators 36, but the claimed subjectmatter is not limited to any such number of actuators 36. Each actuator36 may include a sensor 64 that measures linear displacement, forcesapplied on the actuator 36, or various other desired parameters. Eachactuator 36 shown in the examples of the figures is a hydraulicactuator, but in the alternative, the actuators may be an electric,pneumatic, electro-mechanical, piezoelectric, magnetorestrictive or anysuitable combination thereof. The lengths, forces, and pressuresassociated with each actuator 36 can be independently set, measured,controlled, displayed, recorded, and transmitted.

Each actuator 36 may also include at least one pressure fitting 65(shown in FIG. 1, but omitted from subsequent Figures for claritypurposes). The pressure fittings 65 are attached to a conventionalpressure hose 67 in communication with respective pressure sensors incommunication with the control system 90. The actuators 36 can bepositioned at an angle β relative to the frame axis 14. The angle β canbe selected based on the size and stiffness of frame 12, as well asvarious other monitored parameters. In the embodiments shown throughoutthe figures, angle β is about 23 degrees; however, the presentlydisclosed subject matter is not limited to any such angle. In otherconfigurations of the gyratory compactor apparatus 10 may utilizecarriage plates 32, 34 with geometries that are not limited to a flatsurface and can include any kind of three dimensional shape. Angle β canthen be suitably optimized for each given configuration. As will bedescribed in more detail herein, the sensors 64 may be in communicationwith an appropriately programmed processor of control system 90 formonitoring and controlling various desired data parameters. Transducersmeasure the pressure of hydraulic fluid about pressure fittings 65.However, other types of pressure transducers can be used such as loadcells, a calibrated extensometer, electrical power measurement, or othersuitable instruments. In instrumented gyratory compactor apparatus, atleast one of the actuators including but not limited to lateral motionactuators 36, ram rod 54, and translation mechanism 40 have theirposition and associate force can be measured, recorded, controlled,stored, displayed, transmitted, and analyzed, in real-time or atpredetermined positions, or predetermined times. The related measurementor information may be displayed, stored, transmitted, and analyzedinside the gyratory compactor apparatus 10 via the control system 90.This information can also be transmitted with a wire or wirelessly to anexternal computation unit for analysis, storage, printing, display.These measurements can then in turn be used to control the actuator 36location and/or exerted force. In some embodiments, the gyratorycompactor apparatus 10 may not include load sensors. However, theconfiguration may be upgraded to include some or all pressure sensors.

As shown in greater detail in FIG. 3, each actuator 36 attaches to thesecond carriage plate 34 and enables motion in at least two degrees offreedom. In the embodiment shown in FIG. 3, a slot 19 is formed in aflange extending from the second carriage plate 34. The slot 19 houses aswiveling joint 21, which may be a conventional heim joint type design.A corresponding slot 17 is also formed in the first mounting plate 16for attaching to the other end of each actuator 36, which also houses aswiveling joint 23. The corresponding swiveling joint can be configuredto minimize backlash, to prevent non linear behavior in position duringmotion and under different forces, loads and/or moments. A plurality ofclamping rods 35 span between the first carriage plate 32 and the secondcarriage plate 34 for providing additional support to the mold engagingdevice 30 and for providing slideable translation of the second carriageplate 34 about the frame axis 14.

The mold-engaging device 30 is shown in greater detail in FIGS. 4 and 5.As shown in FIG. 5, the mold-engaging device 30 includes the firstcarriage plate 32 and the spaced-apart second carriage plate 34. Theplurality of clamping rods 35 extend between a periphery of the firstcarriage plate 32 and of periphery of the second carriage plate 34. Themold-engaging device 30 is shown without engagement with the mold 70 inFIG. 4 and in engagement with the mold 70 in FIG. 5. Engagement of themold 70 is effectuated by actuating the translation mechanism 40, whichthen that imparts translation to the first carriage plate 32 about theframe axis 14 until the first carriage plate 32 contacts the mold 70 andadditionally provides clamping forces to the mold 70. As themold-engaging device 30 relies primarily on the ends of the mold 70 forclamping purposes, the mold shape, height, and diameter is notrestricted and various other mold designs may be employed. Also, themajority of clamping forces are imparted to the first mounting plate 16such that flexure of the frame and other components of the gyratorycompactor apparatus 10 is reduced or better controlled.

A cross-sectional view of the mold-engaging device 30 and pivotedsupport 22 is shown in FIG. 6. In some embodiments, the pivoted support22 is a gimbal of the type known in the art, but in appropriatecircumstances could be a spherical bearing or any other joint orstructure capable of rotation within an appropriate range of directions.A first clamping plate 46 and a second clamping plate 47 collectivelyform a pair of clamping plates. A plurality of sleeves 39 are carried bythe first clamping plate 46. The sleeves 39 are configured for slideablyreceiving a respective clamping rod 35 within. The translation mechanism40 functions by having a piston 42 slideably positioned within acylinder 44 that is defined within a housing 45. The piston 44 is incontact with the first clamping plate 46 by rod 43 such that an increasein pressure within the piston cylinder 44 imparts downward forces ontothe first clamping plate 46 and causes upward translation of the secondclamping plate 47. This is turn causes translation of clamping rods 35away from the mold and thus imparts translation of the second carriageplate 34 until the second carriage plate 34 comes into mating engagementwith the mold 74, thereby securing the mold 70 in place between thefirst carriage plate 32 and the second carriage plate 34. While thetranslation mechanism 40 is shown in the figures as a hydraulicactuator, the presently claimed subject matter is not limited to anyspecific design and could utilize electromechanical, mechanical,pneumatic, or other suitable designs, or combinations thereof.

In alternate embodiments, an alternate translation mechanism can engagethe second carriage plate 34 and impart compression forces via at leastone pneumatic, hydraulic, piezoelectric, or magneto restrictiveactuators or any combination thereof.

An internal angle α is defined between a mold axis 72 formed about acentral vertical of the mold 70 and the frame axis 14 as shown in FIG.7A and FIG. 7B. Moreover, the gyratory orbit generated by the actuator36 can be controlled so that the internal angle α is consistent as afunction of time in order to take into account the variability of theframe 12 flexure, relative changes in the position between the firstcarriage plate 32 and second carriage plate 34, and the position of theram rod 54. FIG. 7A details the gyratory compactor apparatus 10 gyratingthe mold 70 towards a first direction, while FIG. 7B shows the gyratorycompactor apparatus 10 gyrating the mold one half of a rotation beyondthat which is shown in FIG. 7A. The internal angle α measured may bemeasured instantaneously, time-delayed, or averaged over a predeterminedperiod of time.

As shown in FIGS. 8 and 9, the ram rod 54 is provided proximal thesecond mounting plate 50. The ram rod 54 acts to provide compressiveforces to the mold 70 about the frame axis 14. A linear displacementdevice 56 may be provided for measuring displacement relative to the ramrod 54. An anti-rotate plate 60 is positioned on a distal end of the ramrod 54 for torsional rigidity to retard rotating forces from rotation ofthe ram rod 54. The anti-rotate plate 60 includes a plurality ofspaced-apart support beams 62 that are each carried on a first end abouta periphery of the anti-rotate plate 60 and that are each carried on asecond end at the second mounting plate 20. These beams 62 act to retardrotating forces from rotation of the ram rod and thus provide a moreaccurate and controlled testing environment.

A mold 70 of the type for use with the gyratory compactor apparatus 10is shown in FIG. 10 and FIG. 11. The mold 70 includes a cylinder 71, afirst peripherally extending flange 73 at a first end 91 and secondperipherally extending flange 74 at a second opposing end 93 of thecylinder 71. The mold 70 is adapted for receiving a volume of materialto be compacted within a void, generally designated 76, defined withinthe cylinder 71. The mold 70 is typical of the type of mold routinelyemployed within relevant compactor industries, however, the presentlyclaimed subject matter is not limited to any particular shape of mold.

As shown in FIG. 13, at least one of the carriage plates 32, 34 maydefine textural features 86 that are configured to increase axialfriction to aid with clamping of the mold and to reduce the axial forcesthat must be generated to maintain the mold 70 within the mold-engagingdevice 30. The textural features 86 may be grooves, such as are shown as87 in FIG. 13, etching, carving, chiseling, sandblasting, or any othersuitable feature, or the features may be added by the addition of atleast one layer containing anti slippage or friction increasingproperties. Similarly, as shown in FIG. 14, at least one of surfaces 91or 93 of the mold 70 may also possess textural features 88 or at leastone. A representative embodiment showing grooves 89 is presented in FIG.14, but any suitable textural feature 88 may be employed. In thisregard, flanges 73 and 74 may not be necessary to use with the gyratorycompactor apparatus 10, as the textural features 86, 99 may be all thatis required to hold the mold 70 between the first carriage plate 32 andthe second carriage plate 34.

Operation of the gyratory compactor apparatus and preparation of thetesting specimen will now be described. A suitable sample of material tobe compacted is first prepared by mixing appropriate aggregates.Typically, the gyratory compactor apparatus will be used for mixingasphalt. When mixing asphalt, the asphalt composition is heated to apredetermined temperature along with the mold 70. The mold 70 andasphalt are not typically heated above 350 degrees Fahrenheit, but inappropriate circumstances may be heated to any suitable temperaturedepending on the material to be tested.

As shown in FIG. 11, a first puck (not shown) can be inserted into thecavity 76 of the mold, and then a first piece of specimen paper 77 isplaced on the first puck within the cavity 76 of the mold 70. The heatedasphalt mixture 75 or soil mixture specimen is then placed within themold 70. A second piece of specimen paper 77 is placed above specimen 75before finally placing a second puck 78 within the cavity 76 of the mold70. Both the first puck and the second puck 78 are typically heated withthe mold 70 and specimen 75 to ensure proper heat expansion andcontraction, as well as to maintain a consistent environmental testingstandard.

The mold 70 is then inserted between the first carriage plate 32 and thesecond carriage plate 34. The translation mechanism 40 is then actuatedto impart translation of the second carriage plate 34 until the mold 70is firmly held between the first carriage plate 32 and the secondcarriage plate 34 as described in the description accompanying FIGS. 4,5, and 6. Once the mold 70 is correctly positioned and engaged withinthe mold-engaging device 30, the operator selects a set of predeterminedparameters such as gyratory internal angle α, the pressure of the ramrod 54, the displacement of the ram rod 54, and the number of gyrations,among other parameters. Gyration and compaction continue until a desiredparameter is met, such as displacement of the ram rod 54 or number ofgyrations.

In appropriate circumstances, the gyratory compactor apparatus 10monitors the compaction pressure of the ram rod 54, and if compactionpressures of the ram rod fall within or out of a desired, predeterminedrange of pressures, the gyratory compactor apparatus 10 may be designedto cease operation at that time.

Once the desired amount of compaction of the specimen 75 is achieved,the compacted specimen is removed from the mold 70. Appropriate testingsuch as determining density and other desired test parameters are thencarried out on the compacted specimen.

The ram rod 54 is configured such that the operator of the gyratorycompactor apparatus 10 can select the compressive characteristics of theram rod 54. As shown in FIG. 12, the ram rod 54 applies verticalcompressive forces to the mold 70 and is configured to travel in avertical, longitudinal direction as represented by an upwards arrow and“y.” The ram rod 54 is also configured for rotational movement about theframe axis 14 as represented by “w.” The ram rod 54 outputs thesecompressive forces by communicating with the control system 90. Thecontrol system may have a wave or signal generator in communicationtherewith. In some embodiments such as is shown in FIG. 12, the ram rod54 may have a compressive function that approximates a wavefunctionincluding but not limited to a sinusoidal, as shown in graph (a) in FIG.12, triangular, as shown in graph (b) in FIG. 12, saw-tooth, as shown ingraph (c) in FIG. 12, square, as shown in graph (d) in FIG. 12, or otherdesired waveforms, and in other embodiments, may also be configured toapproximate other parameters associated with such waveform, includingbut not limited to the amplitude, phase, offset, dynamic range, timedelay, and other various parameters. In each of the graphs shown in FIG.12, the vertical axis represents vertical displacement (y) of the ramrod 54 as a function of time (t).

The control system 90 and the various techniques described herein may beimplemented with hardware or software or, where appropriate, with acombination of both. The control system 90 may be a circuit boardappropriately configured and mounted to apparatus 10. Further, thecontrol system 90 may be separated from apparatus 10 in the form of amachine such as a computer in communication with components on theapparatus. Thus, the gyratory compactor apparatuses and associatedmethods of the disclosed embodiments, or certain aspects or portionsthereof, may be controlled by the control system 90, alone or togetherwith various other components, executing program code (i.e.,instructions) embodied in tangible media, such as floppy diskettes,CD-ROMs, hard drives, or any other machine-readable storage medium. Forexample, the program code can be loaded into and executed by a machine,such as a computer, and the machine becomes an apparatus for practicingembodiments of the presently disclosed subject matter. In the case ofprogram code execution on programmable computers, the computer willgenerally include a processor, a storage medium readable by theprocessor (including volatile and non-volatile memory and/or storageelements), at least one input device and at least one output device. Oneor more programs are preferably implemented in a high level proceduralor object oriented programming language to communicate with a computersystem. However, the program(s) can be implemented in assembly ormachine language, if desired. In any case, the language may be acompiled or interpreted language, and combined with hardwareimplementations.

The described methods and apparatus may also be embodied in the form ofprogram code that is transmitted over some transmission medium, such asover electrical wiring or cabling, through fiber optics, or via anyother form of transmission, wherein, when the program code is receivedand loaded into and executed by a machine, such as an EPROM, a gatearray, a programmable logic device (PLD), a client computer, a videorecorder or the like, the machine becomes an apparatus for practicingthe presently disclosed subject matter. When implemented on ageneral-purpose processor, the program code combines with the processorto provide a unique apparatus that operates to perform the processing ofthe presently disclosed subject matter.

An important aspect to operation of gyratory compactor apparatuses aspresently disclosed is calibration of various aspects of the orbitalmotion, internal angle, loads, mechanical moments exerted inside themold onto the sample between the applied motion imparted and measured onor by the actuators or carriage plate assemblies and the loads,pressure, forces, moments applied on or by actuators and carriage plateassemblies, and the like. In an embodiment of the presently disclosedsubject matter, a gyratory angle, either internal or external angle, canbe measured at a high sampling rate. For example, a suitably configureddevice, such as a RAM or DAV, can measure the angle of gyration, orgyratory angle, at a high sampling rate. The measured internal angle canbe used for determining adjustments to actuation of the actuators of agyratory compactor apparatus as disclosed herein to impart to the mold atarget orbit.

Due to the non isotropic flexure of various components of the overallassembly of a gyratory compactor apparatus, the motion perceived by thesample inside the mold can be significantly different from a targetorbit for the mold. Apparatuses disclosed herein can use algorithms toconvert the difference between the actual orbital motion of the mold andthe target orbital motion for the mold into a corrected motion of theactuators to ensure proper motion. For example, one typical error is dueto the slight misalignment of the actuators with respect to each other,the correction can then lead to a slight change in the time delay, alsoreferred to as phase delay, between the actuators' motion. When theframe and/or ram of an apparatus exhibit significant difference inflexure in one or more directions, the shape of the waveform applied tothe actuators control can be applied to correct for the resulting errorof orbit. The type, value, correction and calibration of the waveformsmay vary as the shape, dynamic range of the orbit, the amount ofcompressive loads change. The correction can be applied to at least oneof the actuators, ram, and clamping system. The correction and theupdated external orbit and related parameters can then be stored,printed, displayed, and/or analyzed.

FIG. 15 is a flow chart of an exemplary process for calibrating agyratory compactor apparatus in accordance with an embodiment of thepresently disclosed subject matter. In this example, reference is madeto other embodiments of the gyratory compactor apparatus disclosedherein and shown in other figures. Referring to FIG. 15, a mold isplaced in engagement with a mold-engaging device (step 100). Forexample, the mold 70 shown in FIGS. 7A and 7B can be placed inengagement with the mold-engaging device 30 shown in FIG. 4 inaccordance with the disclosure herein. The mold can contain a sample ormaterial to be tested during compaction.

At step 102, compaction and orbital motion are applied to a sample inthe mold. For example, the ram rod 54 shown in FIG. 1 can applyrotational movement and compressive forces to the mold about the frameaxis. The control system 90 can control movement of the ram rod 54.

At step 104, lateral displacement of the mold relative to an axis of aframe of the gyratory compactor apparatus is imparted by actuation ofone or more actuators. As a result, a gyratory angle between the frameaxis and the mold axis is defined. For example, referring to FIGS. 7Aand 7B, the control system 90 can control actuation of the actuators 36such that the internal angle α is defined between a mold axis 72 formedabout a central vertical of the mold 70 and the frame axis 14. Steps 102and 104 can occur simultaneously.

At step 106, the gyratory angle is measured. For example, themeasurement of the gyratory angle, either internal or external angle,can be measured instantaneously for each rotation of the mold relativeto each rotation of the mold. The measurement of the gyratory angle mayalso be averaged for each rotation of the mold. The measurement can beperformed directly without limitation by one or more inclinometersoperative to the inside or outside of the mold or an internal anglemeasurement device such as a RAM or DAV, or the measurement can beperformed indirectly by the location of at least one of the carriageplate assemblies or the position of at least one actuator lengths. Thesemeasurements can be taken continuously or at least one predeterminedposition in the orbit of the motion, or at least one predetermined timeof operation including at predetermined intervals of times. A typicalparameter to be concerned with for calibration is the synchronizationdelay between the forces/position between the at least one actuators inorder to generate a circular motion, without such proper synchronizationthe orbit perceived by the sample under test may be elliptical in shape.

At step 108, a force and/or pressure exerted on the mold can bemeasured. For example, the sensors 64 or various other sensors may be incommunication with the control system 90 for monitoring various dataparameters of the gyratory compactor apparatus. Further, for example,various types of pressure transducers can be used for measure forceand/or pressure on the mold such as load cells, a calibratedextensometer, electrical power measurement, or other suitableinstruments. The lateral motion actuators 36, ram rod 54, and/ortranslation mechanism 40 may also have their positions and associatedforces measured, recorded, stored, displayed, transmitted, and analyzed,in real-time or at predetermined positions, or predetermined times.

At step 110, adjustments to actuation of one or more actuators aredetermined based one or a combination of the measured gyratory angle, atarget angle, the measured force, and the measured pressure. Forexample, the control system 90 can apply an algorithm for determiningadjustments to the actuators 36 based on the measured gyratory angle anda target angle. An operator of the apparatus may desire that thegyratory angle between the apparatus frame and the mold axis form atarget angle in a particular testing run. To do so, the operator mayprogram the control system 90 with the desired target angle such thatthe algorithm uses the programmed target angle and one or more acquiredmeasurements to determine actuator adjustments.

At step 112, actuation of one or more of the actuators is controlledbased on the determined adjustments. For example, the control system 90can utilize adjustments calculated by the algorithm to determine inputsfor the actuators 36. As a result, when the actual gyratory anglediffers from the target gyratory angle, the actuators 36 can becontrolled to make corrections such that the actual gyratory anglematches the target gyratory angle.

Measurement of forces applied to a mold of a gyratory compactorapparatus and measurements of geometric changes to a frame of theapparatus may not be sufficient to estimate a complete set of forcesapplied to the mold. For example, a moment simulation device, such as aRAM or DAV, can be inserted into a mold and can be utilized to obtain asimulated moment measurement when compressive forces are applied to it.Such a simulation can be performed with or without orbital motion of themold. However, the measurements may not be accurate. In accordance withan embodiment of the presently disclosed subject matter, a method isprovided to calibrate the moment simulation device using suchmeasurements by using one or more of pressure and/or force measurementson the lateral actuators (e.g., actuators 36), compressive actuators(e.g., used to move the ram rod 54), and clamping actuators applied tothe gyratory compactor apparatus. The calibration can be performed underdifferent values of angle, orbit shape, motion, and static positions.The calibration can utilize a model or algorithm that is not limited topolynomials of any order, and it may also include non-separablecomponents of non-linear mathematical functions. Moreover, these valuesmay be interpolated or extrapolated to values inside or outside therange of parameters that are described. Moreover, these calibrationvalues can be estimated and set by default based on the previousgeometric angle calibration. Based upon this calibration, the shearmoment, shear pressure, shear force, and eccentricity can be displayed,stored, analyzed, and printed. FIG. 16 is a flow chart of an exemplaryprocess for calibrating a gyratory compactor apparatus in accordancewith this embodiment of the presently disclosed subject matter. In thisexample, reference is made to other embodiments of the gyratorycompactor apparatus disclosed herein and shown in other figures.

Referring to FIG. 16, a mold is placed in engagement with amold-engaging device (step 150). For example, the mold 70 shown in FIGS.7A and 7B can be placed in engagement with the mold-engaging device 30shown in FIG. 4 in accordance with the disclosure herein. The mold cancontain a sample or material to be tested during compaction.

At step 152, a moment simulation device is inserted in the mold to applya moment. For example, a RAM or DAV can be inserted in the mold 70 forapplying a moment.

At step 154, compaction and orbital motion are applied to a sample inthe mold. For example, the ram rod 54 shown in FIG. 1 can apply alateral displacement and compressive forces to the mold about the frameaxis. The control system 90 can control movement of the ram rod 54. Thelateral displacement may be static or dynamic orbital motion.

At step 156, lateral displacement of the mold relative to an axis of aframe of the gyratory compactor apparatus is imparted by actuation ofone or more actuators. As a result, a gyratory angle between the frameaxis and the mold axis is defined. For example, referring to FIGS. 7Aand 7B, the control system 90 can control actuation of the actuators 36such that the internal angle α is defined between a mold axis 72 formedabout a central vertical of the mold 70 and the frame axis 14. Steps 154and 156 can occur simultaneously.

At step 158, actuator loads, pressures, and moments exerted on the moldare measured. For example, the sensors 64 or various other sensors maybe in communication with the control system 90 for monitoring variousdata parameters of the gyratory compactor apparatus. Further, forexample, various types of pressure transducers can be used for measureforce and/or pressure on the mold such as load cells, a calibratedextensometer, electrical power measurement, or other suitableinstruments. The lateral motion actuators 36, ram rod 54, and/ortranslation mechanism 40 may also have their positions and associatedforces measured, recorded, stored, displayed, transmitted, and analyzed,in real-time or at predetermined positions, or predetermined times.

At step 160, actuator measurements are filtered, and calibrationgenerated. The calibration can be generated to convert thesemeasurements into moment exerted into sample based on selectedcalibration function. For example, the control system 90 can determine arelationship between the measured force applied by one or more of theactuators 36 and the applied moment.

At step 162, one or more corrections for different compaction loads andmotion types can be one or both of interpolated and extrapolated. Theinterpolation functions may be polynomial with or without separablecomponents, logarithmic, exponentional or any combinations of linear ornon-linear mathematical functions. At step 164, one or more calibrationcoefficients can be stored.

According to one embodiment, the gyratory compactor apparatus caninclude a display configured to display one of error of the measurementof the actual moment from a target moment, a three-dimensionalrepresentation of the actual moment, shear pressure, shear moment,eccentricity, eccentricity vector, or any other information related tomoments, information relative to the passing/failing of criteria oftarget moment information, and average values or information relative tomoment. The control system 90 can communicate with the display. Thedisplay can also display one of the measurement of the actual angle orcorresponding error from the prescribed value, the three-dimensionalrepresentation of the angle, average angle per gyration. A memory of thecontrol system 90 can store one of the measurement of the actual angleor corresponding error from the prescribed value, the three-dimensionalrepresentation of the angle, average angle per gyration, or anyinformation related to angle or internal angle or external angle, orinformation relative to passing/failing criteria of target angularinformation, and average values or information relative to angle.

While the embodiments have been described in connection with thepreferred embodiments of the various figures, it is to be understoodthat other similar embodiments may be used or modifications andadditions may be made to the described embodiment for performing thesame function without deviating therefrom. Therefore, the disclosedembodiments should not be limited to any single embodiment, but rathershould be construed in breadth and scope in accordance with the appendedclaims.

1. A method for calibrating a gyratory compactor apparatus configured tocompact and impart a displacement to a sample in a mold that defines amold axis, the gyratory compactor apparatus including at least oneactuator for imparting displacement of the mold relative to alongitudinal axis of the gyratory compactor apparatus, the methodcomprising the steps of: inserting a moment simulation device in a moldto apply a moment; imparting displacement of the mold relative to thegyratory compactor apparatus by actuation of the at least one actuatorto thereby define a gyratory angle between the gyratory compactorapparatus and the mold axis; measuring the actual moment; applying acompression force onto the mold to thereby generate an actual moment;measuring at least one force applied by the at least one actuator; anddetermining a relationship between the measured at least one forceapplied by the at least one actuator and the applied moment.
 2. Themethod according to claim 1, further comprising determining a correctiveparameter for the moment simulation device based on the determinedrelationship.
 3. The method according to claim 1, further comprisingstoring the corrective parameter.
 4. The method according to claim 1,further comprising filtering the measurement of the at least one force.5. The method according to claim 1, further comprising displaying themeasurement of the actual moment.
 6. The method according to claim 1,further comprising one of interpolating and extrapolating at least onecorrection for different predetermined forces exerted on the mold. 7.The method according to claim 1, wherein the at least one forcecomprises shear.
 8. A gyratory compactor apparatus adapted to compactand impart an orbital motion to a sample in a mold that defines a moldaxis, the gyratory compactor apparatus comprising: at least one actuatorconfigured to impart displacement of the mold relative to the gyratorycompactor apparatus to thereby define a gyratory angle between thegyratory compactor apparatus and the mold axis; a device configured toapply a compression force onto the mold; at least one sensor configuredto measure at least one force applied by the at least one actuator; anda control system configured to control the gyratory compactor apparatusto vary the orbital motion to match a predetermined moment to be exertedon the sample.
 9. The gyratory compactor apparatus according to claim 8,wherein the control system is configured to determine a correctiveparameter for the moment simulation device.
 10. The gyratory compactorapparatus according to claim 9, wherein the control system is configuredto store the corrective parameter.
 11. The gyratory compactor apparatusaccording to claim 8, wherein the control system is configured to filterthe measurement of the at least one force.
 12. The gyratory compactorapparatus according to claim 8, further comprising a display configuredto display the measurement of the actual moment.
 13. The gyratorycompactor apparatus according to claim 8, further comprising a displayconfigured to display one of error of the measurement of the actualmoment from a target moment, a representation of the actual moment,shear pressure, shear moment, and eccentricity.
 14. The gyratorycompactor apparatus according to claim 8, further comprising a displayconfigured to display one of the measurement of the actual angle orcorresponding error from the prescribed value, the representation of theangle, and average angle per gyration.
 15. The gyratory compactorapparatus according to claim 8, further comprising a memory configuredto store one of the measurement of the actual angle or correspondingerror from the prescribed value, the representation of the angle, andaverage angle per gyration.
 16. The gyratory compactor apparatusaccording to claim 8, wherein the control system is configured tointerpolate and extrapolate at least one correction for differentpredetermined forces exerted on the mold.
 17. The apparatus according toclaim 8, wherein the at least one force comprises shear.